Surgical cavity drainage and closure system

ABSTRACT

A surgical drain device includes an adhesion matrix of biodegradable polymer material and a plurality of drain tubes attached to the matrix. The device is implanted within a surgical wound to treat the presence of seromas, for example, and is used to promote drainage, tissue adhesion, and wound closure. The drain tubes converge into a common collection tube that leads wound fluid outside the body under gravity feed or negative pressure applied to the collection tube. The matrix contains an array of apertures that allow tissue contact across the device. The device also can include a coating of surgical adhesive and a tissue anchoring system of hooks or barbs. The device can be used with a negative pressure system to further improve the drainage band can also be used with a wound dressing. The device and systems containing the device are particularly useful to promote the healing of surgical wounds from abdominal surgery.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No.14/111,977, filed Oct. 15, 2013, which was a 35 U.S.C. § 371 nationalstage filing of International Application No. PCT/US2012/033608, filedApr. 13, 2012, which claims the priority to U.S. Application No.61/475,945, filed Apr. 15, 2011. The entire contents of the aboveapplications being incorporated herein by reference.

BACKGROUND OF THE INVENTION

A variety of systems have been proposed for draining surgical wounds.The efficacy of such systems has been limited, however, especially forlarger surgical spaces or those in which certain characteristics, suchas motion or shape, or certain physiological characteristics, such aslymphatic drainage or low protein exist. Seroma is a frequentcomplication following surgery, and can occur when a large number ofcapillaries have been severed, allowing plasma to leak from the bloodand lymphatic circulation. Surgical wounds that can lead to seromaformation include wounds resulting from surgery involving an abdominalflap, such as abdominoplasty surgery, breast reconstruction surgery,panniculectomy, and ventral hernia repair.

Available surgical drain devices suffer from several deficiencies,particularly when applied following abdominal flap surgery. They fail todrain fluid adequately, are prone to clogging, and fail to promotetissue adhesion within the wound. Thus, there remains a need to developimproved treatments for surgical wounds. The need is particularly acutein abdominal surgery, such as for the prevention and treatment ofseromas, but also for any surgical wound predisposed to conditions ofexcess fluid drainage or tissue motion, or benefitting from tissueadhesion needs, such as pressure ulcers or wounds resulting from atissue harvesting procedure.

SUMMARY OF THE INVENTION

The invention provides a surgical drain device for the prevention andtreatment of seromas as well as for general use in promoting drainage ofsurgical wounds and wound closure. The drain device includes a pluralityof drain tubes disposed on a substrate termed an “adhesion matrix,”which is designed to promote tissue adhesion within the seroma or woundspace. The adhesion matrix has a conformable configuration and is madeof a compliant material having planar surfaces that can curve to adaptto the shape of the wound space.

In a preferred embodiment, the adhesion matrix contains a plurality ofapertures, or gaps in the matrix material, which allow tissue contactacross the matrix, so as to promote adhesion and wound closure. Thus, atissue surface on a first side of the matrix can directly contact atissue surface on a second, or opposite, side of the matrix to promoterapid healing and stabilization of the wound. The number, size anddistribution of the apertures extending through the matrix can beselected based on the geometry of the wound. For abdominal wounds, forexample, the drain tubes can be positioned in a fan shaped array with aplurality of three or more tubes extending from a manifold. The matrixand/or the tubing can be cut or shaped by the user to conform to theshape of the wound. The matrix can also be used as a medication carrierto assist in the administration of a drug to a patient. The matrix canoptionally include a layer of adhesive on at least a portion of any ofits surfaces. The drain tubes can be removed from the device oncedrainage flow is sufficiently reduced, and the adhesion matrix canremain within the body, where it is degraded and absorbed over time,remaining in place to optimize tissue healing. The matrix can comprise aporous biodegradable polymer material. As the plurality of tubes extendfrom a single exit site into the wound with spaced apart distal ends, auser can readily remove all the tubes simultaneously from the wound.

The surgical drain device can include a tissue anchoring system, wherebythe device is mechanically attached to surrounding tissues by an arrayof surface barbs or hooks. These surface structures can be located onany exposed surface of the adhesion matrix. When the device isimplanted, the surrounding tissues can be pressed against the barbs orhooks to embed them within the tissue and anchor the device. The use ofsurface barbs or hooks can be used in combination with a surgicaladhesive, providing a much stronger bond between tissue layers than theadhesive alone, and providing temporary adhesion while the adhesivesets. The structure of the hooks can have various forms depending on thetissue they are intended to bind. Longer hooks can be used for looselybound tissues such as fat or connective tissue, while shorter hooks canbe used for denser tissues such as muscle. Anchors with more rigid stemscan be utilized to penetrate denser tissues.

Another aspect of the invention is a system for surgical wound drainage.The system includes the drain device described above together with avacuum source, such as a pump, and a tube connecting the vacuum sourceto the drain tubes of the drain device. The system optionally also caninclude a fluid trap to collect drained fluid and a control unit tomonitor and control the application of vacuum and the collection offluid. Further components of the system can include a vacuum or pressuregauge, a flow meter, and a computer to monitor vacuum and flow and toregulate vacuum or flow.

Another aspect of the invention is a method for treating or preventing aseroma, or promoting the drainage or closure of a surgical wound. Themethod includes positioning the drain device described above into aseroma, or a surgical wound, such as a wound at risk of forming aseroma, and allowing the device to drain fluid from the wound for aperiod of time. The device can include surgical adhesive and/or barbs orhooks on its surface to create adhesion between tissue layers within thewound and to anchor the device in place. Drainage can be by gravity flowor can be vacuum assisted by attaching a vacuum source to the draintubes of the device, using a manifold to merge the flow paths of thedrain tubes to a common drain tube for collection. Negative pressureapplied to the drain tubes can be used to hold the tissue layers aboveand below the device together until a surgical adhesive has set, oruntil the wound healing process binds the tissues together. Theapplication of negative pressure further facilitates contact betweentissue on opposite sides of the matrix through the apertures in thematrix to promote tissue adhesion. This improves the rate of healingwhile at the same time providing for drainage. Optionally, the draintubes of the device can be removed from the body after drainage flow isreduced, thereby reducing the burden for resorption by the body. Removalof the drain tubes can be facilitated by the inclusion of drain tubechannels, or drain tube release tabs, within the adhesion matrix.Release of the drain tubes is then accomplished by sliding the tubes outof the channels or appropriately maneuvering the drain tube assembly tobreak release tabs. The adhesion matrix is allowed to remain in theseroma or surgical wound where it is resorbed over time.

The flow rate from the drain tubes can be regulated by flow controlelements. The flow rate can also be measured or the pressure of fluidscan be measured by ultrasound devices or by other methods. The systemcan also be used in conjunction with wound dressings that can also beattached to a negative pressure source to remove fluids from the wound.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a drawing of the abdomen of a patient who has an abdominalflap wound resulting from abdominal surgery.

FIG. 2 shows a drawing of a surgical drain device according to theinvention which has been inserted through an abdominal flap wound.

FIG. 3 shows a cross-sectional view of a surgical drain device accordingto the invention installed in the abdomen of a human patient betweensubcutaneous tissue and a layer of abdominal muscle.

FIG. 4 is a schematic diagram of a surgical wound drainage systemaccording to the invention.

FIGS. 5A-5G are illustrations of embodiments of a surgical drain deviceaccording to the invention, depicting the disposition of drain tubeswithin the device and features of the drain tubes and polymer matrix.FIGS. 5A-5D show representative embodiments having different mechanismsof attaching drain tubes to the polymer matrix. In FIG. 5A the draintubes are encased within drain tube channels, and in FIG. 5B the draintubes are attached via retaining structures. In FIG. 5C the drain tubesare glued onto the matrix, and in FIG. 5D the drain tubes are spotwelded onto the matrix. FIGS. 5E and 5F show embodiments havingdifferent configurations of drain tubes within drain tube channels. FIG.5G shows a drain tube embodiment having lateral apertures for collectionof fluid.

FIGS. 6A-C show illustrations of embodiments of an adhesion matrixhaving different types of tissue contact apertures. FIG. 6D is anillustration of an adhesion matrix embodiment possessing tissue anchorson its surface. FIG. 6E shows a cross-sectional view of the adhesionmatrix of FIG. 6D.

FIGS. 7A-7C are cross-sectional illustrations of different embodimentsof the drain device positioned within a wound or seroma. Theseembodiments include one or more layers of adhesive.

FIG. 8 illustrates a process sequence of performing wound closuretreatment in accordance with preferred embodiments of the invention.

FIG. 9A illustrates a wound drainage and wound dressing system in whichthe wound dressing does not overlie the drainage exit site.

FIG. 9B illustrates a wound drainage and dressing system in which thewound dressing overlies the drainage exit site.

FIGS. 10A and 10B illustrate cross-sectional view of drainage exit tubeassemblies that can be used in preferred embodiments of the invention.

FIG. 11 is a side view of a tissue anchoring mesh in accordance withpreferred embodiments of the invention.

FIG. 12 is a process flow diagram illustrating a method of using a wounddressing and drainage system in accordance with preferred embodiments ofthe invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a surgical drain device, system, andmethod that allow fluid to be drained from surgical wounds and promotethe healing of the wound. Preferred embodiments are used to prevent ortreat seromas, for example. The drain device features a set of draintubes that are attached to a substrate, herein referred to as anadhesion matrix, that is designed to promote adhesion of tissues withinthe wound or seroma and to encourage cellular infiltration into thedevice itself. The drain tubes are distributed across the adhesionmatrix to promote even drainage across the device. To promote optimumdrainage, the drain tubes can be uniformly distributed across theadhesion matrix. The drainage device can be left in place within thewound for a period of time, e.g., until fluid seepage diminishes, afterwhich the drain tubes can be withdrawn from the device and removed fromthe patient without disturbing the adhesion matrix, which is left inplace to biodegrade or become incorporated into the healing process. Thedevice efficiently promotes the healing of even large area wounds suchas those resulting from abdominal flap surgery.

A surgical drain device according to the invention is inserted throughan incision in the skin of a patient and placed within a wound formedduring surgery. A first purpose is to drain fluid during the surgicalprocedure. The system can be left in place and to provide drainage fordays or even weeks following surgery. The device can be used for thetreatment of a seroma, e.g., to drain a seroma and thereby promote itshealing, it can also be used to prevent seroma formation. For example,the drain device can be placed routinely into surgical incision areasimmediately following surgery and used to drain the area and aid in theprevention of seroma formation. Alternatively, the device can be placedinto a seroma that has already formed by opening the seroma andinstalling the device. The use of the drain device is understood to“prevent” seroma formation even if it merely reduces the likelihood ofseroma formation. Similarly, the use of the drain device is understoodto “treat” seroma formation even if it merely increases the likelihoodthat the seroma will heal. FIG. 1 shows an abdominoplasty or abdominalflap wound (10) in a patient resulting from abdominal surgery. FIG. 2shows surgical drain device 20 inserted through abdominal flap wound 10and into the space occupied by seroma 15.

The device according to the invention includes a number of removabledrain tubes 30 attached at their proximal ends to manifold 40, whichconnects to a vacuum source through vacuum tubing 50. The drain devicecollects and removes fluid from the abdominal region or from the fluidspace of a seroma through the drain tubes, which divert the fluidoutside the patient through the aid of a vacuum source. The number ofdrain tubes can vary depending upon the needs of the device, includingthe amount of fluid to be drained and the size of the wound and shape ofthe device. Typically, the device will contain from 2 to about 20 draintubes. In a preferred embodiment, the device contains preferably atleast 3 tubes, and for larger areas such as the abdomen, for example,from about 5 to about 12 tubes.

The drain tubes can be fabricated from any biocompatible thermoplasticor thermoset material. Examples include surgical grade silicone rubber,polyurethane, polyamide, polyimide, PEEK (polyether ether ketone),polycarbonate, PMMA (polymethylmethacrylate), and polyvinylchloride. Thedrain tubes are intended to be removed after fluid build-up has reducedto a level that is stable without drainage. However, in an alternativeembodiment, the drain tubes can be made of a biodegradable material andcan be left in place. The drain tubes can be flexible so as to conformto the tissues surrounding the device and to accommodate movement of thepatient without causing discomfort. The drain tubes can be open ended orclose ended. In a preferred embodiment, the drain tubes are close endedand possess apertures or holes along their length for the uptake offluid.

FIG. 3 shows drain device 20 installed in the abdomen betweensubcutaneous tissue 70 and a layer of abdominal muscle 80 and associatedfascia 90. While this position can be used following abdominal flapsurgery, other anatomical locations of the device are also possible andare contemplated as suitable uses of the invention.

FIG. 4 schematically depicts a system for drainage of a seroma throughan abdominal flap wound. System 21 includes drain device 20, having aplurality of drain tubes 30 attached to adhesion matrix 25 andconfigured so as to drain the full extent of the seroma. The drain tubesare connected at their proximal ends to manifold 40, which is in turnconnected through vacuum tubing 50 to a vacuum pump 130 or other vacuumsource. Fluid 125 drained from the wound can be optionally accumulatedin fluid trap 120. Vacuum pump or other vacuum source 130 can includeone or more electronic devices, such as a microprocessor with memory andsoftware, to monitor the vacuum level, pneumatic resistance, and/orfluid removal amount or rate. The electronic device(s) also can be usedto control the operation of the system over time according touser-defined parameters, according to a preset program, or in responseto data collected on vacuum, resistance, and/or fluid removal.

FIGS. 5A-5G depict representative embodiments of a drain deviceaccording to the invention, showing several possible configurations ofthe drain tubes within the device. FIG. 5A shows an embodiment in whicheach drain tube 30 is disposed within a separate drain tube channel 35.The drain tube channels are embedded within or attached to the surfaceof adhesion matrix 25 and determine the orientation and distribution ofthe drain tubes within the device. In a preferred embodiment, the draintube channels, and consequently the drain tubes, are evenly distributedacross the surface area of the drain device, as shown in FIG. 4. Thesecan extend in a generally radial distribution from one edge or region onthe matrix to enable use of a single exit tube from the wound. However,the drain tubes can be unevenly distributed if desired, e.g., toincrease the drainage capacity or rate from specific areas of thedevice. The use of drain tube channels ensures that the drain tubesremain in position within the patient and ensures that the drain tubescan be removed easily at the appropriate time, without disrupting thewound healing process. Drain tube channels require a mechanism to acceptfluid and pass it on to the drain tubes within. Suitable mechanismsinclude using apertures or holes of any desired shape and distributionalong the length of the channels (see, e.g., apertures 33 on channels 35in FIG. 6D), and using a porous material to form the drain tube channels(see drain tube channels 35 in FIGS. 5E and 5F, constructed of a porouspolymer matrix).

Several alternative embodiments are also contemplated which lack draintube channels. FIG. 5B depicts the use of retaining structures 35 ainstead of channels in order to removably attach the drain tubes to theadhesion matrix, while allowing removal of the tubes by sliding or bybreaking off the retaining structures. The retaining structures can haveany form compatible with their function. FIG. 5C shows an embodiment inwhich drain tube 20 is held in place by layer of adhesive 31, and thetube is fitted within a depression on the surface of adhesion matrix 25.In the related embodiment shown in FIG. 5D, the drain tube is held inthe matrix depression by spot welds or adhesion points 32, which can bebroken through suitable manipulation to remove the tubes.

FIGS. 5E and 5F present cross-sectional views of a portion of theadhesion matrix 25 of an embodiment of a drain device according to theinvention. The adhesion matrix contains regions for receiving draintubes or can include one or more drain tube channels 35 which surroundsdrain tubes 30, having lumen 34, through which seroma or other woundfluid is removed. A round Blake drain is depicted as the drain tube inFIG. 5E, and a flattened version in FIG. 5F. A variety of drain tubeprofile shapes are possible, including oval, elliptical, square,rectangular, triangular, flattened, compound (i.e., having 2 or moreparallel lumens, interconnected or separated), or irregular. The draintubes optionally can be coated with a lubricant on their outer surfacesto facilitate their removal from the channels.

In a preferred embodiment the drain tubes possess openings or apertures33 along their length to permit fluid to enter for drainage. FIG. 5Gdepicts one such embodiment. The relative surface area and distributionof such apertures can be chosen so as to regulate flow through the draintubes. For example, pressure drop (i.e., loss of vacuum) along thelength of the drain tubes can be compensated by increasing the opensurface area or the density of apertures towards the distal end of thedrain tubes. Drain tubes are preferred which have an aperturedistribution that provides an essentially constant rate of fluid uptakealong the length of the drain tubes (e.g., increasing aperture areatowards the distal end), so that uniform drainage is obtained across thedrain device.

Adhesion matrix 25 includes a plurality or matrix of apertures 27 whichallow tissue contact through the drain device. Such tissue contactpromotes wound healing and the sealing of capillaries, which isimportant for treating seromas or preventing their formation. In thedrain device according to the present invention, the promotion of tissuecontact works in combination with fluid drainage to promote woundhealing. The adhesion matrix 25 and its drain tube channels 35preferably are constructed of one or more biodegradable polymermaterials and can be left within the wound, where they stabilize tissueinfiltration and adhesion and thus promote the healing process. Thesize, shape, and distribution of the tissue contact apertures 27 can bevaried according to individual needs. However, greater tissue contactacross the device will promote better adhesion, drainage, and woundclosure. Therefore, it is preferred that at least about 50%, 60%, or70%, and preferably about 75-80% of the total surface area (one side) ofthe drain device remains open in the form of tissue contact apertures.The distribution and spacing of tissue contact apertures can be variedas desired, and the apertures can be the same, similar, or different inshape, size, and distribution across the device. For example, theapertures can be distributed with an average center-to-center spacing inthe range of about 2 mm to about 20 mm or more, and the averageindividual aperture surface area can be in the range from about 1 mm² toabout 5 cm². In a preferred embodiment, the apertures have about 1 cm²average surface area, and their number or their collective surface areabecome progressively larger from the proximal end of the drain device(i.e., near the exit point from the body) toward the distal end of thedevice (deep within the wound or seroma), so that tissue adhesion andwound closure progress from deep within the wound towards the surface ofthe body.

FIGS. 6A-E show several embodiments of the adhesion matrix. A portion ofthe adhesion matrix 25 between two neighboring drain tubes 30 and drainchannels 35 is shown. The embodiment shown in FIG. 6A has a regulararrangement of rectangular apertures 27 to allow tissue contact throughthe device. Circular apertures are shown in FIG. 6B. The embodiment ofFIG. 6C includes apertures 27 that are formed into lateral channels.Fluid flows laterally through these channels toward openings 36 in thedrain tube channels, drawn by the reduced pressure in the drain tubes.As shown in FIGS. 6D and 6E, the surfaces of the adhesion matrix,including the drain channels, can be endowed with an array of hooks orbarbs to promote anchoring of the device to adjacent tissues. In theembodiment shown in FIG. 6E, the hooks on the upper side 28 are longerthan the hooks on the lower side 29. This arrangement can be used wherethe tissues on either side of the device are of different density. Forexample, longer hooks such as about 1.5 to about 3 mm in length arepreferred for less dense tissue, such as subcutaneous fat tissue,whereas shorter hooks such as about 0.5 to about 1.5 mm in length arepreferred for denser tissues such as fascia and muscle.

The adhesion matrix, including any drain tube channels and hooks orbarbs, can be fabricated from a biodegradable polymer material, as thesestructures are intended to remain in place in the patient's body afterremoval of the drain tubes, so as not to disrupt the healing process.Examples of suitable biodegradable or resorbable materials includeVicryl (polyglycolic acid), Monocryl (glycolic acid-s-caprolactonecopolymer), PDS (polydioxanone, PDO), PLA (polylactic acid,polylactide), PLLA (poly-L-lactic acid), PDLA (poly-D-lactic acid), PGA(polyglycolic acid, polyglycolide), PLGA (poly(lactic-co-glycolicacid)), PHB (polyhydroxybutyrate), and PCL (polycaprolactone). In apreferred embodiment, the adhesion matrix, including any drain tubechannels, is formed of an open network of polymer chains that hassufficient porosity to allow infiltration by cells and fluid flow acrossthe material. Cellular infiltration can promote tissue adhesion and thebiodegradation of the polymer after the wound has healed. In someembodiments, the adhesion matrix including any drain tube channels ispermeable to seroma fluid but not permeable to cells. In otherembodiments, the adhesion matrix, including any drain tube channels, ispermeable to fluid and electrolytes but is impermeable to proteins. Thepermeability properties of the matrix polymer material that makes up thebasic substrate of the matrix can be the same or different compared tothe material that makes up the drain tube channels. In a preferredembodiment, the polymer chains, or fibers composed of polymer chains, ofthe adhesion matrix are aligned along an axis substantiallyperpendicular to the axes of the nearest drain tubes. This alignmentpattern promotes the flow of fluid through or along the surface of theadhesion matrix towards the drain tubes.

The adhesion matrix, and thus the overall drain device, can have anyform suitable for insertion into the wound or seroma where it is to beinserted. Generally, the form is that of a thin sheet having anessentially rectangular shape. However, the shape can be rounded,circular, elliptical, oval, or irregular. Preferably the corners arerounded so as to minimize mechanical irritation of surrounding tissues.The size of the device is also determined by the particular use andanatomy of the patient. For example, the adhesion matrix can have anoverall width and length in the range from about 2 cm to 25 cm, such asabout 10 cm×12 cm or about 20 cm×25 cm. The thickness of the adhesionmatrix can be from about 0.5 mm to about 1 cm; where the sheet ofmaterial is preferably less than 5 mm in thickness and preferably theadhesion matrix is about 1-2 mm thick. The thickness of the entire draindevice, including the sheet of the adhesion matrix, drain tubes, and anyhooks or glue pads is about 5 mm or less, 10 mm or less, or about 5-10mm.

The adhesion matrix can be coated with an adhesive material such as asurgical glue either in addition to or instead of using hook or barbstructures that stabilize tissue layers on either side of the draindevice. Any type of surgical adhesive suitable for use within the bodycan be used, including polyethylene glycol polymers, adhesive proteins,gelatin-thrombin mixtures, albumin-glutaraldehyde, and fibrin-basedsealants. Cyanoacrylates are to be avoided, as they cause inflammationif used internally. An adhesive coating can be placed on one or bothsurfaces of the adhesion matrix. Adhesive coatings can be applied to thedevice prior to its placement in a patient, i.e., as part of the devicefabrication process. An adhesive coating can cover all or a portion of asurface of the device. A surgical adhesive can be used in the form of afibrous mat or pad that is soaked with an adhesive composition. The mator pad is preferably fabricated from a biodegradable polymer, such asthe type used to prepare the adhesion matrix. One or more layers ofadhesive material can be placed between the device and surroundingtissue at the time of placement in the patient. FIGS. 7A-7C illustratethe placement of supplemental adhesive layers with the drainage device.In FIG. 7A, adhesive layer or pad 140 has been placed into a wound orseroma adjacent to exposed tissue 150. In FIG. 7B, drainage device 20has been placed onto the adhesive layer as shown in FIG. 7A, and thewound then closed and vacuum applied, so that the device-adhesive padsandwich is surrounded by tissue 150. FIG. 7C depicts the structureobtained if a second adhesive pad or layer 140 is added adjacent to thedrainage device on the opposite side of the first adhesive layer.

The invention also provides a method for treating or preventing a seromaas illustrated in FIG. 8. The method also can be used to promote woundclosure after surgery 210, to prevent infection after surgery, and toimprove the strength and/or cosmetic appearance of a surgical woundafter it has fully healed. A drain device according to the invention ispositioned into a surgical wound 220, such as a wound followingabdominal flap surgery. The device has been sterilized prior toplacement within the wound. Optionally, one or more layers of surgicaladhesive is placed on one or both sides of the device, interfacingbetween the device and surrounding tissue 230. If the device includeshooks or barbs on one or both sides, pressure is applied to the surfaceof the device in order to set the hooks or barbs into the surroundingtissue. The wound is then partially surgically closed at the surface,leaving a single tube exiting the wound. The tube is then attached to avacuum source 240, and vacuum is applied 250 so as to initiate drainagethrough the device. The rate of drainage is controlled by the level ofvacuum applied. The amount of vacuum is sufficient to promote drainagewithout causing damage to the tissues surrounding the implanted device.For example, the vacuum can be in the range from about 75 to 250 mm Hg.After the rate of fluid drainage has decreased to acceptable levels, thevacuum is removed and the drain tubes are removed 260 by slowly pullingthem out through the remaining wound opening, which is subsequentlyclosed. The adhesion matrix remains in the patient and is biodegradedand absorbed over a period of weeks to months.

Illustrated in connection with FIGS. 9A and 9B are uses of a wounddressing in combination with the adhesion matrix or mesh device and anegative pressure drainage system. After placement of the matrix 404, asdescribed in detail herein, the drainage tubing 405 extends through anexit site 409 of the skin 401 of a patient. The wound can frequentlyrequire the use of a wound dressing 402 that is placed externally on theskin of a patient. The wound dressing can either overlie the exit site456 as shown in FIG. 9B, or the wound dressing can be placed laterally(or non-overlying) from the exit site 409 as shown in FIG. 9A. Thetubing 405 can either connect directly to the pump 420, or can utilize aconnector or manifold 412 positioned on or above the skin 401, which canbe connected to the pump 420. A valve 408 can be used to control theapplication of negative pressure. A flow meter can be included at theconnector or manifold 412 or at the valve 408 to measure the fluidremoval rate and total amount of fluid removed. A quantitative measureof the fluid removed can thereby be measured and recorded. Otherdiagnostic measurement devices, such as ultrasound, can also be used tomeasure the amount and location of fluid or seromas within the wound.This information can be used to adjust the amount and distribution ofnegative pressure applied within both the wound using drainage system404, 454 and the wound dressing 402, 452.

Negative pressure can be applied to the wound dressing 402 throughseparate tube 415 that can be attached to the same pump 420 as thedrainage system or a second pump. A valve 406 can be used to regulatepressure to the wound dressing. In the embodiment of FIG. 9B, tube ortubes 458 can exit the wound and attach at connector 462 to theunderside of the dressing 452. A manifold 470 can control thedistribution of negative pressure to both the dressing 452 and thedrainage device 454 using passive or active flow control elements. Themanifold can be attached using a single tube 460 to pump 480. The pump420, 480 can be operated by hand or electronically. The pump can haveinternal electronic control, memory and display features 485 to controlsystem operation and record patient data.

Shown in FIGS. 10A and 10B are preferred embodiments of drainage tubeassemblies that can be used in conjunction with the invention. Thedrainage tubing 405, 458 preferably exits the wound as a single tube oras a cluster of tubes within an outer tube. The outer tube 504 caneither be a flattened shape 500 of a plurality of three or more tubes502 arranged in line as shown in FIG. 10A, or can be circular 520 withdrainage tubes 522 extending within outer tubes 522 to the pump orconnector. In certain applications, it may be advantageous to remove thetubes separately at different times from the drainage system as certainregions may drain more quickly. However, for many wounds it is useful tosimultaneously remove all drainage tubes from the wound.

Shown in FIG. 11 is a side view of an adhesion matrix or mesh 540 usedin preferred embodiments of the invention. It can frequently be usefulto employ such a mesh to facilitate wound adhesion and healing using anabsorbable material that can adhere on both sides to tissues within awound. Frequently, these tissue are of different types on opposite sidesof the mesh. Thus, the mesh can include a conformable layer 542 havingtissue anchors 544, 546 on both sides. However, as one side may be usedto attach to the fatty or adipose tissue on the underside of a flap ofskin, the first plurality of tissue anchors 544 has a shape and rigiditysuitable for attaching to adipose tissue. The second plurality of tissueanchors can be shaped and sized to attach to less compliant tissues suchas fascia or muscle. More rigid hooks or barbs are needed to enable thisattachment.

Shown in FIG. 12 is a sequence of steps in a method 600 of applying adrainage and wound dressing system in accordance with the invention.After performing a procedure 610 on a patient, a wound closure device isinserted 620 into the wound of a patient. This can be a combination ofelements, such as meshes as shown in FIG. 11 in certain regions of thewound, and a drainage and mesh system as described generally herein inregions of the wound requiring drainage of fluid. This can also includethe user 630 of adhesives and/or tissue anchors to enable more directcontact of tissues through the mesh and thereby improve the rate ofhealing. A wound dressing can also be applied 640 to the wound asdescribed herein. A pump can then be attached 650 to the drainage systemand/or the wound dressing and a negative pressure can be applied 660 toone or both elements to drain fluid and promote contact between tissuesthrough the implanted mesh or matrix. The flow rate of fluid througheach tube can be measured and recorded and the presence of fluid can bemonitored 670 by ultrasound or other systems. The drainage tubing can beremoved 680 when the drainage rate diminishes. The wound dressing can bereplaced 690 as needed and can continue to be used to drain 690 thewound.

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and/or detailstherein and equivalents thereof may be made without departing from thespirit and scope of the invention as set forth by the appended claims.

What is claimed is:
 1. A method for treating or preventing a seroma, themethod comprising the steps of: positioning an adhesion matrix into asurgical flap wound, the adhesion matrix comprising a layer ofbiodegradable material having a plurality of spaced apart tissue contactapertures; attaching a negative pressure source to a plurality of draintubes or flow channels, or a combination thereof, on or within saidadhesion matrix, the plurality of drain tubes or flow channels, or saidcombination thereof, extending between one or more apertures in theadhesion matrix, the tissue contact apertures having a size, shape, anddistribution that are configured such that tissue on a first side of theadhesion matrix contacts tissue on a second side of the adhesion matrixthrough one or more of the apertures upon application of negativepressure; draining fluid from the wound for a period of time with oneexternal tube connected to the plurality of drain tubes, flow channels,or said combination thereof, at a single exit site of the wound; andremoving the external tube such that the adhesion matrix remains in thewound.
 2. The method of claim 1 further comprising attaching tissue tothe adhesion matrix with a plurality of tissue anchors.
 3. The method ofclaim 1 further comprising using an adhesive to attach tissue to theadhesion matrix.
 4. The method of claim 1 further comprising applyingsufficient pressure to provide tissue growth through the tissue contactapertures of the adhesion matrix.
 5. The method of claim 4 wherein theapertures comprise at least 50 percent of a total matrix surface area.6. The method of claim 1 further comprising applying a wound dressing tothe wound.
 7. The method of claim 6 further comprising applying anegative pressure to the wound dressing through a manifold.
 8. Themethod of claim 1 further comprising attaching the adhesion matrix witha first plurality of tissue anchors to adipose tissue.
 9. The method ofclaim 1 further comprising attaching the adhesion matrix with a secondplurality of tissue anchors to fascia and/or muscle tissue.
 10. Themethod of claim 1 further comprising measuring a fluid flow rate throughthe external tube.
 11. The method of claim 1 further comprisingmeasuring an amount of seroma within the wound with an ultrasounddevice.
 12. The method of claim 1 wherein the adhesion matrix has fluidchannels that are coupled to the external tube.
 13. The method of claim1 wherein the tissue contact apertures are configured to enable flow offluid laterally into the plurality of drain tubes.
 14. The method ofclaim 1 further comprising attaching a wound dressing to the wound andapplying negative pressure to the wound dressing.
 15. The method ofclaim 1 further comprising attaching the drain tubes to tube receivingregions of the adhesion matrix.
 16. The method of claim 1 furthercomprising: positioning the plurality of drain tubes into the surgicalwound in a body of a subject, each of the drain tubes extending from asingle exit site on the body to a distal end, the tubes beingconnectable to a negative pressure source; and draining fluid from thewound through the drain tubes.
 17. The method of claim 16 wherein theadhesion matrix comprises a biodegradable polymer matrix.
 18. The methodof claim 17 wherein the matrix comprises a mesh with a first pluralityof tissue anchors on a first side and a second plurality of tissueanchors on a second site, the second anchors having a more rigid stemthan the first anchors.
 19. The method of claim 1 further comprisingusing the adhesion matrix with drain channels to receive spaced apartdrain tubes.
 20. The method of claim 16 further comprising using theadhesion matrix with spaced tissue contact apertures to enable flow tothe drain tubes.
 21. The method of claim 16 further comprising using theadhesion matrix with tissue contact apertures of varying size.
 22. Themethod of claim 16 further comprising applying a wound dressing to thewound and using a pump to apply negative pressure to the wound.
 23. Amethod for treating or preventing a seroma, the method comprising thesteps of: positioning a plurality of at least three drain tubes into asurgical flap wound, the plurality of drain tubes having distal endsthat are spaced apart in a fan shaped distribution, each drain tubeincluding apertures along a flexible length of each drain tube such thatfluid within the wound flows through the apertures and into a channel ofat least one of the drain tubes; partially closing the wound such thatthe plurality of drain tubes are held in place in the flap wound in thefan shaped distribution; attaching a negative pressure source to theplurality of drain tubes within the partially closed flap wound with asingle external tube positioned at a single exit site through the skinat the partially closed wound, the single external tube being connectedto the plurality of drain tubes extending between regions of tissue suchthat flap tissue contacts opposing tissue at areas between the pluralityof drain tubes in the fan shaped distribution within the flap wound uponapplication of negative pressure; draining fluid from the wound for aperiod of time with the single external tube at a single exit site ofthe partially closed wound; and removing the external tube and pluralityof drain tubes from the wound.
 24. The method of claim 23 furthercomprising attaching the plurality of drain tubes to an adhesion matrixthat holds the drain tubes in the fan shaped distribution.
 25. Themethod of claim 24 further comprising using an adhesive to attach tissueto the adhesion matrix.
 26. The method of claim 25 further comprisingapplying sufficient pressure to provide tissue growth through aplurality of tissue contact apertures of the adhesion matrix.
 27. Themethod of claim 23 further comprising a manifold positioned external tothe single exit site that connects the single external tube to theplurality of drain tubes.
 28. The method of claim 23 further comprisinga layer with drain channels between adjacent drain tubes within thewound.
 29. The method of claim 23 wherein at least one of the draintubes comprises a lumen having a closed end.
 30. The method of claim 23wherein the attaching step further comprises connecting the singleexternal tube to the negative pressure source that comprises a pumpconnected to a microprocessor that controls a vacuum level and a rate offluid removal in the drain tubes and a memory that stores data, the rateof flow being measured by a flow meter and controlled by a flow valve.31. The method of claim 23 further comprising applying a dressing on asurface of the skin around the wound wherein the dressing overlies theexit site of the wound.
 32. The method of claim 23 wherein the pluralityof tubes exit the wound in a line at a manifold.
 33. The method of claim23 wherein a plurality of five or more drain tubes are connected to amanifold that is coupled to a pump with the single external tube.
 34. Amethod for treating or preventing a seroma, the method comprising thesteps of: positioning a plurality of at least three drain tubes into asurgical flap wound, the plurality of drain tubes having distal endsthat are spaced apart in a fan shaped distribution, each drain tubeincluding apertures along a flexible length of each drain tube such thatfluid within the wound flows through the apertures and into a channel ofat least one of the drain tubes; partially closing the wound such thatthe plurality of drain tubes are held in place in the flap wound in thefan shaped distribution; attaching a negative pressure source to theplurality of drain tubes within the partially closed flap wound with asingle external tube connected to a manifold positioned at a single exitsite wherein the plurality of at least three tubes exit through the skinat the partially closed wound, the single external tube being connectedto the plurality of drain tubes extending between regions of tissue suchthat flap tissue contacts opposing tissue at areas between the pluralityof drain tubes in the fan shaped distribution within the flap wound uponapplication of negative pressure; draining fluid from the wound for aperiod of time with the single external tube at a single exit site ofthe partially closed wound; and removing the external tube and pluralityof drain tubes from the wound.
 35. The method of claim 34 furthercomprising attaching the plurality of drain tubes to an adhesion matrixthat holds the drain tubes in the fan shaped distribution.
 36. Themethod of claim 34 wherein the plurality of at least three tubes connectto the manifold in a line.